An American businessman who worked for years undercover as an FBI confidential witness was blocked by the Obama Justice Department from telling Congress about conversations and transactions he witnessed related to the Russian nuclear industry's efforts to win favor with Bill and Hillary Clinton and influence Obama administration decisions, his lawyer tells The Hill.

Attorney Victoria Toensing, a former Reagan Justice Department official and former chief counsel of the Senate Intelligence Committee, said Tuesday she is working with members of Congress to see if they can get the Trump Justice Department or the FBI to free her client to talk to lawmakers.

“All of the information about this corruption has not come out,” she said in an interview Tuesday. “And so my client, the same part of my client that made him go into the FBI in the first place, says, 'This is wrong. What should I do about it?'”

Toensing said she also possesses memos that recount how the Justice Department last year threatened her client when he attempted to file a lawsuit that could have drawn attention to the Russian corruption during the 2016 presidential race as well as helped him recover some of the money Russians stole from him through kickbacks during the FBI probe.

The undercover client witnessed “a lot of bribery going on around the U.S.” but was asked by the FBI to sign a nondisclosure agreement (NDA) that prevents him from revealing what he knows to Congress, Toensing explained.

When he tried to bring some of the allegations to light in the lawsuit last year, “the Obama Justice Department threatened him with loss of freedom. They said they would bring a criminal case against him for violating an NDA,” she added.